JSFiddle - React, Tailwind, and code Playground

HTML

<table>
  <tr>
    <th>title 1</th>
    <th>title 2</th>
    <th>title 3</th>
  </tr>
  <tr>
    <td>item 1</td>
    <td>item 2</td>
    <td>item 3</td>
  </tr>
  <tr>
    <td>item 1</td>
    <td>item 2</td>
    <td>item 3</td>
  </tr>
  <tr>
    <td>item 1</td>
    <td>item 2</td>
    <td>item 3</td>
  </tr>
  <tr>
    <td>item 1</td>
    <td>item 2</td>
    <td>item 3</td>
  </tr>
</table>

CSS

table {
  border-collapse: seperate;
  border-spacing: 0;
}

tr th,
tr td {
  padding: 20px;
  border-right: 1px solid #000;
  border-bottom: 1px solid #000;
}

tr th {
  border-top: 1px solid #000;
}

tr td:nth-child(1),
tr th:nth-child(1) {
  border-left: 1px solid #000;
}

/* border radius */
tr th:nth-child(1) {
  border-radius: 10px 0 0 0;
}

tr th:nth-last-child(1) {
  border-radius: 0 10px 0 0;
}

tr:nth-last-child(1) td:nth-child(1) {
  border-radius: 0 0 0 10px;
}

tr:nth-last-child(1) td:nth-last-child(1) {
  border-radius: 0 0 10px 0;
}